Antibiotic cycloalkyltetrahydroquinoline derivatives

ABSTRACT

A method of treating a subject for a bacterial infection includes administering to a subject in need of treatment for a bacterial infection an effective amount of a compound represented by structural formula (I), or a pharmaceutically acceptable salt, solvate, or hydrate thereof. The variables in structural formula (I) are described herein.

RELATED APPLICATIONS

This application claims priority to and is a continuation of U.S.Application No. 60/494,669, filed on Aug. 13, 2003, the entire teachingsof which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

In the last century, antibiotics were developed that led to significantreductions in mortality. Unfortunately, widespread use has led to therise of antibiotic resistant bacteria, e.g., methicillin resistantStaphyloccocus aureus (MRSA), vancomycin resistant enterococci (VRE),and penicillin-resistant Streptococcus pneumoniae (PRSP). Some bacteriaare resistant to a range of antibiotics, e.g., strains of Mycobacteriumtuberculosis resist isoniazid, rifampin, ethambutol, streptomycin,ethionamide, kanamycin, and rifabutin. In addition to resistance, globaltravel has spread relatively unknown bacteria from isolated areas to newpopulations. Furthermore, there is the threat of bacteria as biologicalweapons. These bacteria may not be easily treated with existingantibiotics.

Infectious bacteria employ the peptidoglycan biosynthesis pathway, andin particular, depend on MurA(phosphoenolpyruvate:UDP-N-acetyl-D-glucosamine1-carboxyvinyltransferase, EC 2.1.5.7), to catalyze the transformationof uridine diphosphate-N-acetyl-D-glucosamine and phosphoenolpyruvateinto uridine diphosphate-N-acetyl-3-O-(1-carboxyvinyl)-D-glucosamine:

MurA is conserved across both Gram positive and Gram negative bacteria,but is not present in mammalian systems, and is thus a desirable andselective target for new medications.

Therefore, there is a need for new medications that target MurA, wherebyinfections from bacteria dependent on MurA can be treated.

SUMMARY OF THE INVENTION

It has now been found that certain cycloalkyltetrahydroquinolinederivatives strongly inhibit MurA, as shown in Example 3. A number ofthe disclosed inhibitors are found to have antibiotic activity againstbacteria, including drug-resistant bacteria, as shown in Example 4.Furthermore, many of the disclosed MurA inhibitors have lowcytotoxicity, as shown in Example 5. Based on these discoveries,compounds that are MurA inhibitors, methods of treatment with thedisclosed MurA inhibitors, and pharmaceutical compositions comprisingthe disclosed MurA inhibitors, and methods for screening for MurAinhibitors are provided herein.

A method of treating a subject for a bacterial infection includesadministering to a subject in need of treatment for a bacterialinfection an effective amount of a compound represented by structuralformula I:

or a pharmaceutically acceptable salt, solvate, or hydrate thereof.

Ring A is a 5 or 6 membered cycloalkyl or cycloalkenyl group, optionallysubstituted with halogen or optionally halogenated C1-C3 alkyl oralkoxy.

X2 and X3 are each carbon, or one is nitrogen and the other is carbon.

Rings B and C are optionally and independently substituted at anysubstitutable ring carbon, provided that one or two substitutable ringcarbons in Rings B and C are substituted with an acidic group.

In another embodiment, the acidic group is selected from —(CO)OH,—(CS)OH, —(SO)OH, —SO₃H, —OSO₃H, —P(OR^(a))(OH), —(PO)(OR^(a))(OH),—O(PO)(OR^(a))(OH), or —B(OR^(a))(OH), wherein R^(a) is —H or optionallysubstituted aryl, aralkyl, heteroaryl, heteroaralkyl, or C1 to C4 alkyl.Typically, the acidic group is —(CO)OH, —(CS)OH, —(SO)OH, —SO₃H, —OSO₃H,or preferably, —(CO)OH.

Another embodiment is a method of identifying a MurA inhibitor,including contacting MurA with phosphoenolpyruvate and a test compound,under conditions suitable for reaction between the MurA enzyme and thesubstrate phosphoenolpyruvate, and determining a reaction rate betweenthe phosphoenolpyruvate and MurA. The test compound is identified as aMurA inhibitor when the rate of reaction in the presence of the testcompound is less than a reaction rate in the absence of the testcompound. More preferably, the method includes conducting the reactionin the presence of MurB and uridine 5′-diphospho-N-acetylglucosamine. Ina preferred embodiment, the method of identifying compounds as MurAinhibitors is combined with one or more assays for antibiotic activity.Such assays are well known in the art, and can include, for example,contacting bacteria of interest with a test compound under conditionsotherwise suitable for bacterial growth, and determining if the testcompound has antibacterial activity.

The invention is useful for treating (therapeutically orprophylactically) bacterial infections, particularly infections causedby bacteria that depend on the peptidoglycan biosynthesis pathway, andmore particularly, infections caused by bacteria that express the MurAenzyme. Furthermore, it can be useful against bacteria that havedeveloped antibiotic resistance, especially multiple drug resistantstrains, because it is believed to act through a: different mechanismthan existing, widely used antibiotics.

DETAILED DESCRIPTION OF THE INVENTION

The invention is generally related to methods, compounds, andpharmaceutical compositions for treating and preventing bacterialinfections. In particular, the invention relates to substitutedcycloalkyltetrahydroquinoline derivatives that are MurA inhibitors.

In preferred embodiments, the MurA inhibitor of the method isrepresented by one of structural formulas I-a to I-c or I-a″:

In I-a″, Z is —H or a C1 to C4 alkyl group.

In I-b, Y is optionally substituted C1 to C4 alkyl, C1 to C4 alkoxy,phenyl, pyridyl, or —NR^(j) ₂, wherein each R^(j) is independently —H,C1 to C4 alkyl, aryl, or aralkyl, or NR^(j) ₂ is a nonaromaticheterocycle.

In structural formulas I-a to I-c and I-a″, Ring B is optionallysubstituted at any substitutable ring carbon.

In more preferred embodiments, the MurA inhibitor is represented by oneof structural formulas I-a′ to I-c′:

The variables R1, R2, R3 and R4 are independently —H, halogen, —NO₂,—CN, —(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4alkyl, C1 to C4 alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6 alkoxyalkyl;provided that, for I-b′, at least one of R1 to R4 is an acidic group,e.g., —CO₂H. In a preferred embodiment of I-a′, at least one of R1 to R4is —CO₂H, and the remainder of R1 to R4 are as described above.

Each R^(b) and R^(d) is independently —H or optionally substituted aryl,aralkyl, heteroaryl, heteroaralkyl, or C1 to C4 alkyl, and each R^(c) isindependently —H or optionally substituted C1 to C4 alkyl, aryl, oraralkyl, or NR^(c) ₂ is an optionally substituted nonaromaticheterocycle. More typically, each R^(b), R^(c), and R^(d) isindependently —H, or optionally substituted C1 to C4 alkyl or phenyl, oreach NR^(c) ₂ is an optionally substituted morpholinyl, piperidyl, orpiperazyl. Preferably, each R^(b), R^(c) and R^(d) is independently —Hor C1 to C4 alkyl; or NR^(c) ₂ is a nonaromatic heterocycle.

In preferred embodiments of I-a′, I-b′, and I-c′, at least two of R1 toR4 are —H, or more typically, at least two of R1, R2, and R4 are —H.More typically two, and preferably three of R1 to R4 are —H, or two ofR1, R2, and R4 are —H.

More preferably for I-a′, one or two of R1 to R4 are each independentlyhalogen —(CO)R^(b), —(CO)OR^(b), —(CO)NR^(c) ₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂,—NR^(d)(CO)PhNR^(d)(CO)R^(b), or optionally substituted phenyl, benzyl,pyridyl, methylpyridyl, or optionally halogenated C1 to C4 alkyl or C1to C4 alkoxy. In another preferable embodiment of I-a′, R1, R2, R3, andR4 are independently —H, —(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b),—(CS)OR^(b), —(CS)R^(b), —(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b),—P(OR^(b))₂, —(PO)(OR^(b))₂, —O(PO)(OR^(b))₂, —B(OR^(b))₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, or nonaromatic heterocycle. Morepreferably, one or two of R1 to R4 are each independently —(CO)R^(b),—(CO)OR^(b), —(CO)NR^(c) ₂, —NR^(c) ₂, —NR^(d)(CO)R^(b),—NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —NR^(d)(CO)PhNR^(d)(CO)R^(b), oroptionally substituted phenyl, benzyl, pyridyl, or methylpyridyl;

More preferably, for I-b′, R1 to R4 are as described in the precedingparagraph, provided that at least one of R1 to R4 is an acidic group,e.g., —CO₂H.

More preferably for I-c′, R1, R2, and R4 are independently —H, —F, —Cl,—Br, —NO₂, —CN, —(CO)R^(b), —(CO)NR^(c) ₂, —NR^(c) _(2,)NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or optionally halogenated C1 to C4 hydroxy alkyl, C1 toC4 alkyl, or C1 to C4 alkoxy.

In other preferred embodiments of I-a′ and I-b′, at least one of R1 toR4 is —(CO)OR^(b), e.g., —CO₂H or a C1-C4 carboxylic ester thereof. Moretypically, at least one of R1 to R4 is —CO₂H, or preferably, one of R1to R3 is —CO₂H.

Specific examples of MurA inhibitors of the present invention are thecompounds in Table 1.

Also included in the present invention are pharmaceutical compositionscomprising the disclosed MurA inhibitors, (e.g., I-b, I-c, I-a′ to I-c′,and I-a″). The present invention also includes novel MurA inhibitorsdisclosed herein (e.g., I-b, I-c, I-a′ to I-c′, and I-a″), orpharmaceutically acceptable, salts, solvates or hydrates thereof.

A “subject” includes mammals, e.g., humans, companion animals (e.g.,dogs, cats, birds, aquarium fish, reptiles, and the like), farm animals(e.g., cows, sheep, pigs, horses, fowl, farm-raised fish and the like)and laboratory animals (e.g., rats, mice, guinea pigs, birds, aquariumfish, reptiles, and the like). Alternatively, the subject is awarm-blooded animal. More preferably, the subject is a mammal. Mostpreferably, the subject is human.

A subject in need of treatment has a bacterial infection (or has beenexposed to an infectious environment where bacteria are present, e.g.,in a hospital) the symptoms of which may be alleviated by administeringan effective amount of the disclosed MurA inhibitors. For example, asubject in need of treatment can have an infection for which thedisclosed MurA inhibitors can be administered as a treatment. In anotherexample, a subject in need of treatment can have an open wound or burninjury, or can have a compromised immune system, for which the disclosedMurA inhibitors can be administered as a prophylactic. Thus, a subjectcan be treated therapeutically or prophylactically. More preferably, asubject is treated therapeutically.

Typically, the subject is treated for a bacterial infection caused by abacteria of a genus selected from Allochromatium, Acinetobacter,Bacillus, Campylobacter, Chlamydia, Chlamydophila, Clostridium,Citrobacter, Escherichia, Enterobacter, Enterococcus, Francisella,Haemophilus, Helicobacter, Klebsiella, Listeria, Moraxella,Mycobacterium, Neisseria, Proteus, Pseudomonas, Salmonella, Serratia,Shigella, Stenotrophomonas, Staphyloccocus, Streptococcus,Synechococcus, Vibrio, and Yersina.

More preferably, the subject is treated for a bacterial infection fromAllochromatium vinosum, Acinetobacter baumanii, Bacillus anthracis,Campylobacter jejuni, Chlamydia trachomatis, Chlamydia pneumoniae,Clostridium spp., Citrobacter spp., Escherichia coli, Enterobacter spp.,Enterococcus faecalis., Enterococcus faecium, Francisella tularensis,Haemophilus influenzae, Helicobacter pylori, Klebsiella spp., Listeriamonocytogenes, Moraxella catharralis, Mycobacterium tuberculosis,Neisseria meningitidis, Neisseria gonorrhoeae, Proteus mirabilis,Proteus vulgaris, Pseudomonas aeruginosa, Salmonella spp., Serratiaspp., Shigella spp., Stenotrophomonas maltophilia, Staphyloccocusaureus, Staphyloccocus epidermidis, Streptococcus pneunmoniae,Streptococcus pyogenes, Streptococcus agalactiae, Yersina pestis, andYersina enterocolitica, and the like.

Preferably, the subject is treated for a bacterial infection caused by abacterium that expresses a peptidoglycan biosynthesis pathway, and inparticular, expresses the enzyme encoded by the MurA/MurZ gene. Numerousstudies have demonstrated that the MurA gene and its paralog MurZ areconserved across a range of Gram positive and Gram negative bacteria;see, for example, Schonbrunn E, Eschenburg S, Krekel F, Luger K, AmrheinN. (2000) Biochemistry. 2000 Mar. 7;39(9):2164-73; Baum E Z, MontenegroD A, Licata L, Turchi I, Webb G C, Foleno B D, Bush K. (2001) AntimicrobAgents Chemother. 2001 November;45(11):3182-8; Kim D H, Lees W J,Kempsell K E, Lane W S, Duncan K, Walsh C T. (1996) Biochemistry. 1996Apr. 16;35(15):4923-8; and Skarzynski T, Mistry A, Wonacott A,Hutchinson S E, Kelly V A, Duncan K. (1996) Structure. 1996 Dec.15;4(12):1465-74. The entire teachings of these documents areincorporated herein by reference.

As used herein, the term MurA, referring to the gene or the enzymethereby encoded, encompasses both MurA and its paralog MurZ. The enzymesare given various names in the art, including, for example: MurAtransferase; MurZ transferase; UDP-N-acetylglucosamine1-carboxyvinyl-transferase; UDP-N-acetylglucosamine enoylpyruvyltransferase; UDP-N-acetyl glucosamine enolpyruvyltransferase;enoylpyruvate transferase;phosphoenolpyruvate-UDP-acetylglucosamine-3-enolpyruvyltransferase;phosphoenolpyruvate:UDP-2-acetamido-2-deoxy-D-glucose2-enoyl-1-carboxyethyltransferase; phosphoenolpyruvate:uridinediphosphate N-acetyl glucosamine enolpyruvyltransferase;phosphoenolpyruvate:uridine-5′-diphospho-N-acetyl-2-amino-2-deoxyglucose3-enolpyruvyltransferase; phosphopyruvate-uridinediphosphoacetylglucosamine pyruvatetransferase; pyruvate-UDP-acetylglucosamine transferase; pyruvate-uridine diphospho-N-acetyl glucosaminetransferase; pyruvate-uridine diphospho-N-acetyl-glucosaminetransferase; or pyruvic-uridinediphospho-N-acetylglucosaminyltransferase.

As used herein, the term MurB, referring to the gene or the enzymethereby encoded, is given various names in the art, including, forexample: UDP-N -acetylmuramate dehydrogenase, MurB reductase;UDP-N-acetylenol pyruvoyl glucosamine reductase;UDP-N-acetylglucosamine-enoylpyruvate reductase; UDP-GlcNAc-enoylpyruvate reductase; uridinediphosphoacetylpyruvoylglucosamine reductase; uridinediphospho-N-acetylglucosamine-enolpyruvate reductase; uridine-5′-diphospho-N-acetyl-2-amino-2-deoxy-3-O-lactylglucose:NADP-oxidoreductase

The systematic name typically given for MurA/MurZ isphosphoenolpyruvate:UDP-N-acetyl-D-glucosamine1-carboxyvinyltransferase, and the IUBMB systematic classification is EC2.5.1.7. The systematic name typically given for MurB isUDP-N-acetylmuramate:NADP+oxidoreductase, and the IUBMB systematicclassification is EC 1.1.1.158. See International Union of Biochemistryand Molecular Biology online at www.chem.qmul.ac.uk/iubmb/.

In other embodiments, bacterial growth can be retarded, modulated, orprevented by employing an effective amount of the disclosed MurAinhibitors. Numerous bacteria can express the MurA enzyme. Bacteria thatexpress MurA can include, for example, actinobacteria, bacteroids,chlamydia, cyanobacteria; firmicutes, e.g., bacillales, clostridia, andlactobacillales; fusobacteria; green sulfur bacteria; hyperthermophilicbacteria; proteobacteria, e.g., alpha, beta, delta, epsilon, and gamma;radioresistant bacteria; and spirochetes.

For example, actinobacteria can include, Bifidobacterium longum,Corynebacterium efficiens, Corynebacterium glutamicum, Mycobacteriumbovis, Mycobacterium leprae, Mycobacterium tuberculosis (e.g., CDC1551and H37Rv (lab strain)), Streptomyces coelicolor, Tropheryma whipplei(e.g., Twist, TW08/27); and the like.

Examples of bacteroids include Bacteroides thetaiotaomicron and thelike.

Chlamydia can include, e.g., Chlamydophila caviae, Chlamydia muridarum,Chlamydophila pneumoniae (e.g., AR39, J138, CWL029, Chlamydiatrachomatis, and the like.

Examples of cyanobacteria can include Anabaena sp. PCC7120 (Nostoc sp.PCC7120), Synechocystis sp. PCC6803, Thermosynechococcus elongates, andthe like.

Firmicutes, e.g., bacillales can include Bacillus cereus, Bacillushalodurans, Bacillus subtilis, Listeria innocua, Listeria monocytogenes,Oceanobacillus iheyensis, Staphylococcus aureus (e.g., MW2, N315, andMu50), Staphylococcus epidermidis, and the like.

Firmicutes, e.g., clostridia, can include Clostridium acetobutylicum,Clostridium perfringens, Clostridium tetani, Thermoanaerobactertengcongensis, and the like.

Firmicutes, e.g., lactobacillales, can include Enterococcus faecalis,Lactococcus lactis, Lactobacillus plantarum, Streptococcus agalactiae(e.g., 2603 and NEM316), Streptococcus mutans, Streptococcus pyogenes(e.g., MGAS315 (serotype M3), SF370 (serotype M1), SSI-1 (serotype M3),and MGAS8232 (serotype M18)), Streptococcus pneumoniae (e.g., TIGR4 andR6), and the like.

Fusobacteria can include Fusobacterium nucleatum, and the like.

Green sulfur bacteria can include Chlorobium tepidum, and the like

Hyperthermophilic bacteria can include Aquifex aeolicus, Thermotogamaritime, and the like.

Examples of alpha proteobacteria can include Agrobacterium tumefaciensC58 (Cereon), Bradyrhizobium japonicum, Brucella melitensis, Brucellasuis, Caulobacter crescentus, Mesorhizobium loti, Rickettsia conorii,Rickettsia prowazekii, Sinorhizobium meliloti, and the like.

Examples of beta proteobacteria can include Nitrosomonas europaea,Neisseria meningitidis (e.g., Z2491 (serogroup A) and MC58 (setogroupB), Ralstonia solanacearum, and the like.

Examples of delta/epsilon proteobacteria can include Campylobacterjejuni, Helicobacter pylori (e.g., J99 and 26695), and the like.

Examples of gamma proteobacteria can include Buchnera aphidicola (e.g.,Baizongia pistaciae), Buchnera aphidicola (e.g., Schizaphis graminum),Buchnera sp. APS (e.g., Acyrthosiphon pisum), Coxiella burnetii,Escherichia coli (e.g., CFT073, O157 EDL933, K-12 W3110, K-12 MG1655,and O157 Sakai), Haemophilus influenzae, Pseudomonas aeruginosa,Pasteurella multocida, Pseudomonas putida, Pseudomonas syringae pv.,Shigella flexneri 301 (serotype 2a), Shewanella oneidensis, Salmonellatyphimurium, Salmonella typhi (e.g., Ty2, CT18), Vibrio cholerae, Vibrioparahaemolyticus, Vibrio vulnificus, Wigglesworthia brevipalpis,Xanthomonas axonopodis, Xanthomonas campestris, Xylella fastidiosa(e.g., 9a5c and Temecula1), Yersinia pestis (e.g., CO92 and KIM), andthe like.

Radioresistant bacteria can include Deinococcus radiodurans, and thelike

Spirochetes can include Borrelia burgdorferi, Leptospira interrogans,Treponema pallidum, and the like.

In one embodiment, a subject is also concurrently treated for a fungalinfection, for example, a fungal infection caused by a pathogenicdermatophyte, e.g., a species of the genera Trichophyton, Tinea,Microsporum, Epidermophyton and the like; or a pathogenic filamentousfungus, e.g., a species of genera such as Aspergillus, Histoplasma,Cryptococcus, Microsporum, and the like; or a pathogenic non-filamentousfungus, e.g., a yeast, for example, a species of the genera Candida,Malassezia, Trichosporon, Rhodotorula, Torulopsis, Blastomyces,Paracoccidioides, Coccidioides, and the like. Preferably, the subject isconcurrently treated for a fungal infection resulting from a species ofthe genera Aspergillus or Trichophyton. Species of Trichophyton include,for example, T. mentagrophytes, T. rubrum, T. schoenleinii, T.tonsurans, T. verrucosum, and T. violaceum. Species of Aspergillusinclude, for example, A. fumigatus, A. flavus, A. niger, A. amstelodamiA. candidus, A. carneus, A. nidulans, A oryzae, A. restrictus, A.sydowi, A. terreus, A. ustus, A. versicolor, A. caesiellus, A. clavatus,A. avenaceus, and A. deflectus. More preferably, the subject isconcurrently treated therapeutically for a fungal infection caused by aspecies of the genus Aspergillus selected from A. fumigatus, A. flavus,A. niger, A. amstelodami, A. candidus, A. carneus, A. nidulans, Aoryzae, A. restrictus, A. sydowi, A. terreus, A. ustus, A. versicolor,A. caesiellus, A. clavatus, A. avenaceus, and A. deflectus. Even morepreferably the subject is concurrently treated therapeutically for afungal infection caused by Aspergillus fumigatus or Aspergillus niger,and most preferably, Aspergillus fumigatus.

An “effective amount” of a compound of the disclosed invention is thequantity which, when administered to a subject in need of treatment,improves the prognosis of the subject, e.g., delays the onset of and/orreduces the severity of one or more of the subject's symptoms associatedwith a bacterial infection. The amount of the disclosed compound to beadministered to a subject will depend on the particular disease, themode of administration, co-administered compounds, if any, and thecharacteristics of the subject, such as general health, other diseases,age, sex, genotype, body weight and tolerance to drugs. The skilledartisan will be able to determine appropriate dosages depending on theseand other factors. Effective amounts of the disclosed compoundstypically range between about 0.01 mg/kg per day and about 100 mg/kg perday, and preferably between 0.1 mg/kg per day and about 10 mg/kg/day.Techniques for administration of the disclosed compounds of theinvention can be found in Remington: the Science and Practice ofPharmacy, 19^(th) edition, Mack Publishing Co., Easton, Pa. (1995), theentire teachings of which are incorporated herein by reference.

A “pharmaceutically acceptable salt” of the disclosed compound is aproduct of the disclosed compound that contains an ionic bond, and istypically produced by reacting the disclosed compound with either anacid or a base, suitable for administering to a subject.

For example, an acid salt of a compound containing an amine or otherbasic group can be obtained by reacting the compound with a suitableorganic or inorganic acid, such as hydrogen chloride, hydrogen bromide,acetic acid, perchloric acid and the like. Compounds with a quaternaryammonium group also contain a counteranion such as chloride, bromide,iodide, acetate, perchlorate and the like. Other examples of such saltsinclude hydrochlorides, hydrobromides, sulfates, methanesulfonates,nitrates, maleates, acetates, citrates, fumarates, tartrates (e.g.(+)-tartrates, (−)-tartrates or mixtures thereof including racemicmixtures), succinates, benzoates and salts with amino acids such asglutamic acid.

Salts of compounds containing a carboxylic acid or other acidicfunctional group can be prepared by reacting with a suitable base. Sucha pharmaceutically acceptable salt may be made with a base which affordsa pharmaceutically acceptable cation, which includes alkali metal salts(especially sodium and potassium), alkaline earth metal salts(especially calcium and magnesium), aluminum salts and ammonium salts,as well as salts made from physiologically acceptable organic bases suchas trimethylamine, triethylamine, morpholine, pyridine, piperidine,picoline, dicyclohexylamine, N, N′-dibenzylethylenediamine,2-hydroxyethylamine, bis-(2-hydroxyethyl)amine,tri-(2-hydroxyethyl)amine, procaine, dibenzylpiperidine,N-benzyl-β-phenethylamine, dehydroabietylamine,N,N′-bisdehydroabietylamine, glucamine, N-methylglucamine, collidine,quinine, quinoline, and basic amino acid such as lysine and arginine.

Certain compounds and their salts may also exist in the form ofsolvates, for example hydrates, and the present invention includes eachsolvate and mixtures thereof.

As used herein, a “pharmaceutical composition” is a formulationcontaining the disclosed compounds in a form suitable for administrationto a subject. The pharmaceutical composition can be in bulk or in unitdosage form. The unit dosage form can be in any of a variety of forms,including, for example, a capsule, an IV bag, a tablet, a single pump onan aerosol inhaler, or a vial. The quantity of active ingredient (i.e.,a formulation of the disclosed compound or salts thereof) in a unit doseof composition is an effective amount and may be varied according to theparticular treatment involved. It may be appreciated that it may benecessary to make routine variations to the dosage depending on the ageand condition of the patient. The dosage will also depend on the routeof administration. A variety of routes are contemplated, includingtopical, oral, pulmonary, rectal, vaginal, parenternal, transdermal,subcutaneous, intravenous, intramuscular, intraperitoneal andintranasal.

The compounds described herein, and the pharmaceutically acceptablesalts thereof can be used in pharmaceutical preparations in combinationwith a pharmaceutically acceptable carrier or diluent. Suitablepharmaceutically acceptable carriers include inert solid fillers ordiluents and sterile aqueous or organic solutions. The compounds will bepresent in such pharmaceutical compositions in amounts sufficient toprovide the desired dosage amount in the range described herein.Techniques for formulation and administration of the disclosed compoundsof the invention can be found in Remington: the Science and Practice ofPharmacy, above.

For oral administration, the disclosed compounds or salts thereof can becombined with a suitable solid or liquid carrier or diluent to formcapsules, tablets, pills, powders, syrups, solutions, suspensions andthe like.

The tablets, pills, capsules, and the like contain from about 1 to about99 weight percent of the active ingredient and a binder such as gumtragacanth, acacias, corn starch or gelatin; excipients such asdicalcium phosphate; a disintegrating agent such as corn starch, potatostarch or alginic acid; a lubricant such as magnesium stearate; and/or asweetening agent such as sucrose, lactose or saccharin. When a dosageunit form is a capsule, it may contain, in addition to materials of theabove type, a liquid carrier such as a fatty oil.

Various other materials may be present as coatings or to modify thephysical form of the dosage unit. For instance, tablets may be coatedwith shellac, sugar or both. A syrup or elixir may contain, in additionto the active ingredient, sucrose as a sweetening agent, methyl andpropylparabens as preservatives, a dye and a flavoring such as cherry ororange flavor, and the like.

For parental administration of the disclosed compounds, or salts,solvates, or hydrates thereof, can be combined with sterile aqueous ororganic media to form injectable solutions or suspensions. For example,solutions in sesame or peanut oil, aqueous propylene glycol and the likecan be used, as well as aqueous solutions of water-solublepharmaceutically-acceptable salts of the compounds. Dispersions can alsobe prepared in glycerol, liquid polyethylene glycols and mixturesthereof in oils. Under ordinary conditions of storage and use, thesepreparations contain a preservative to prevent the growth ofmicroorganisms.

In addition to the formulations previously described, the compounds mayalso be formulated as a depot preparation. Suitable formulations of thistype include biocompatible and biodegradable polymeric hydrogelformulations using crosslinked or water insoluble polysaccharideformulations, polymerizable polyethylene oxide formulations, impregnatedmembranes, and the like. Such long acting formulations may beadministered by implantation or transcutaneous delivery (for examplesubcutaneously or intramuscularly), intramuscular injection or atransdermal patch. Preferably, they are implanted in, or applied to, themicroenvironment of an affected organ or tissue, for example, a membraneimpregnated with the disclosed compound can be applied to an open woundor burn injury. Thus, for example, the compounds may be formulated withsuitable polymeric or hydrophobic materials, for example, as an emulsionin an acceptable oil, or ion exchange resins, or as sparingly solublederivatives, for example, as a sparingly soluble salt.

For topical administration, suitable formulations may includebiocompatible oil, wax, gel, powder, polymer, or other liquid or solidcarriers. Such formulations may be administered by applying directly toaffected tissues, for example, a liquid formulation to treat infectionof conjunctival tissue can be administered dropwise to the subject'seye, a cream formulation can be administer to a wound site, or a bandagemay be impregnated with a formulation, and the like.

For rectal administration, suitable pharmaceutical compositions are, forexample, topical preparations, suppositories or enemas.

For vaginal administration, suitable pharmaceutical compositions are,for example, topical preparations, pessaries, tampons, creams, gels,pastes, foams or sprays.

In addition, the compounds may also be formulated to deliver the activeagent by pulmonary administration, e.g., administration of an aerosolformulation containing the active agent from, for example, a manual pumpspray, nebulizer or pressurized metered-dose inhaler. Suitableformulations of this type can also include other agents, such asantistatic agents, to maintain the disclosed compounds as effectiveaerosols.

The term “pulmonary” as used herein refers to any part, tissue or organwhose primary function is gas exchange with the external environment,i.e., O₂/CO₂ exchange, within a patient. “Pulmonary” typically refers tothe tissues of the respiratory tract. Thus, the phrase “pulmonaryadministration” refers to administering the formulations describedherein to any part, tissue or organ whose primary function is gasexchange with the external environment (e.g., mouth, nose, pharynx,oropharynx, laryngopharynx, larynx, trachea, carina, bronchi,bronchioles, alveoli). For purposes of the present invention,“pulmonary” is also meant to include a tissue or cavity that iscontingent to the respiratory tract, in particular, the sinuses.

A drug delivery device for delivering aerosols comprises a suitableaerosol canister with a metering valve containing a pharmaceuticalaerosol formulation as described and an actuator housing adapted to holdthe canister and allow for drug delivery. The canister in the drugdelivery device has a head space representing greater than about 15% ofthe total volume of the canister. Often, the polymer intended forpulmonary administration is dissolved, suspended or emulsified in amixture of a solvent, surfactant and propellant. The mixture ismaintained under pressure in a canister that has been sealed with ametering valve.

For nasal administration, either a solid or a liquid carrier can beused. The solid carrier includes a coarse powder having particle size inthe range of, for example, from about 20 to about 500 microns and suchformulation is administered by rapid inhalation through the nasalpassages. Where the liquid carrier is used, the formulation may beadministered as a nasal spray or drops and may include oil or aqueoussolutions of the active ingredients.

In addition to the formulations described above, a formulation canoptionally include, or be co-administered with one or more additionaldrugs, e.g., other antibiotics, anti-inflammatories, antifungals,antivirals, immunomodulators, antiprotozoals, steroids, decongestants,bronchodialators, and the like. For example, the disclosed compound canbe co-administered with drugs such as such as ibuprofen, prednisone(corticosteroid) pentoxifylline, Amphotericin B, Fluconazole,Ketoconazol, Itraconazol, penicillin, ampicillin, amoxicillin, and thelike. The formulation may also contain preserving agents, solubilizingagents, chemical buffers, surfactants, emulsifiers, colorants, odorantsand sweeteners.

The term “aryl” group, (e.g., the aryl groups represented by R1 to R4)refers to carbocyclic aromatic groups such as phenyl, naphthyl,tetrahydronaphthyl, anthracyl, and the like. The term “heteroaryl” group(e.g., the heteroaromatic groups represented by R1 to R4) refers toheteroaromatic groups, for example imidazolyl, isoimidazolyl, thienyl,furanyl, pyridyl, pyrimidyl, pyranyl, pyrazolyl, pyrrolyl, pyrazinyl,thiazolyl, isothiazolyl, oxazolyl, isooxazolyl, 1,2,3-triazolyl,1,2,4-triazolyl, tetrazolyl, benzo[1,3]dioxolyl,2,3-dihydro-benzo[1,4]dioxine, benzopyrimidyl, benzopyrazyl,benzofuranyl, indolyl, benzothienyl, benzoxazolyl, benzoisooxazolyl,benzothiazolyl, benzoisothiazolyl, quinolinyl, isoquinolinyl,benzimidazolyl, tetrahydroquinolinyl, and tetrahydroisoquinolinyl.Preferable aryl and heteroaryl groups include phenyl and pyridyl. Theterm “Ph” indicates a phenyl or a phenylene group, e.g., phenylene in—NR^(d)(CO)PhNR^(d)(CO)R^(b), in R1 to R4.

The term “nonaromatic heterocycle” (e.g., the nonaromatic heterocyclicgroups represented by NR^(c) ₂ or NR^(j) ₂) refers to non-aromatic ringsystems typically having three to eight members, preferably five to six,in which one or more ring carbons, preferably one to four, are eachreplaced by a heteroatom such as N, O, or S. Examples of non-aromaticheterocyclic rings include 3-tetrahydrofuranyl, 2-tetrahydropyranyl,3-tetrahydropyranyl, 4-tetrahydropyranyl, [1,3]-dioxalanyl,[1,3]-dithiolanyl, [1,3]-dioxanyl, 2-tetrahydrothienyl,3-tetrahydrothienyl, N-morpholinyl, 2-morpholinyl, 3-morpholinyl,4-morpholinyl, N-thiomorpholinyl, 2-thiomorpholinyl, 3-thiomorpholinyl,4-thiomorpholinyl, 1 -pyrrolidyl, 2-pyrrolidyl, 3-pyrorolidyl,1-piperazyl, 2-piperazyl, 1-piperidyl, 2-piperidyl, 3-piperidyl,4-piperidyl, 4-thiazolidyl, diazolonyl, N-substituted diazolonyl,1-pthalimidyl, azetidyl, aziridyl, oxaziridyl, oxazolidyl,isooxazolidyl, thiazolidyl, isothiazolidyl, oxazinanyl, thiazinanyl,azepanyl, oxazepanyl, and thiazepanyl. Typically, the nonaromaticheterocycle groups represented by NR^(c) ₂ and NR^(j) ₂ are selectedfrom optionally substituted pyrrolidyl, piperidyl, piperazyl,morpholinyl, and thiomorpholinyl., or preferably, unsubstitutedpiperidyl or morpholinyl.

The disclosed compounds can contain one or more chiral centers. Forexample, in structural formula I, the carbons in common between Rings Aand C, and the carbon in Ring C between the nitrogen and Ring A can eachbe a chiral center. The presence of chiral centers in a molecule givesrise to stereoisomers. For example, a pair of optical isomers, referredto as “enantiomers”, exist for every chiral center in a molecule. A pairof diastereomers exist for every chiral center in a compound having twoor more chiral centers. Where the structural formulas do not explicitlydepict the stereochemistry of each chiral center, for example instructural formulas I-a to I-c, I-a′ to I-c′, I-a″, I-m, and thecompounds in Table 1, it is to be understood that these formulasencompass enantiomers free from the corresponding optical isomer,racemic mixtures, mixtures enriched in one enantiomer relative to itscorresponding optical isomer, a diastereomer free of otherdiastereomers, a pair of diastereomers free from other diasteromericpairs, mixtures of diasteromers, mixtures of diasteromeric pairs,mixtures of diasteromers in which one diastereomer is enriched relativeto the other diastereomer(s) and mixtures of diasteromeric pairs inwhich one diastereomeric pair is enriched relative to the otherdiastereomeric pair(s).

The term “alkyl” (e.g., the alkyl groups represented by R1 to R4, R^(a)to R^(d), and R^(j)), used alone or as part of a larger moiety (e.g.,aralkyl, alkoxy, alkylamino, alkylaminocarbonyl, haloalkyl), is astraight or branched non-aromatic hydrocarbon which is completelysaturated. Typically, a straight or branched alkyl group has from 1 toabout 10 carbon atoms, preferably from 1 to about 5 if not otherwisespecified, Examples of suitable straight or branched alkyl group includemethyl, ethyl, n-propyl, 2-propyl, n-butyl, sec-butyl, tert-butyl,pentyl, hexyl, heptyl or octyl. A C1 to C10 straight or branched alkylgroup or a C3 to C8 cyclic alkyl group can also be referred to as a“lower alkyl” group. An “alkoxy” group refers to an alkyl group that isconnected through an intervening oxygen atom, e.g., methoxy, ethoxy,2-propyloxy, tert-butoxy, 2-butyloxy, 3-pentyloxy, and the like.

The terms “optionally halogenated alkyl”, and “optionally halogenatedalkoxy”, as used herein, includes the respective group substituted withone or more of —F, —Cl, —Br, or —I.

The terms “alkanoyl”, “aroyl”, and the like, as used herein, indicatesthe respective group connected through an intervening carbonyl, forexample, —(CO)CH₂CH₃, benzoyl, and the like. The terms “alkanoyloxy”,“aroyloxy”, and the like, as used herein, indicates the respective groupconnected through an intervening carboxylate, for example, —O(CO)CH₂CH₃,—O(CO)C₆H₅, and the like.

The term “cycloalkyl group” (e.g, the cycloalkyl groups represented byRing A) is a cyclic alkyl group having from 3 to about 10 carbon atoms,preferably from 5 to 6. Examples of suitable cycloalkyl groups includecyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl andcyclooctyl. A “cycloalkoxy” group refers to a cycloalkyl group that isconnected through an intervening oxygen atom, e.g., cyclopentyloxy,cyclohexyloxy, and the like.

The term “cycloalkenyl” (e.g., the cycloalkyl groups represented by RingA) includes nonaromatic cycloalkyl groups that contain one or more unitsof carbon-carbon unsaturation, i.e., carbon-carbon double bonds. Acycloalkenyl group includes, for example, cyclohexenyl or cyclopentenyl.

The terms “aralkyl”, “heteroaralkyl”, “cycloalkylalkyl”, and“nonaromatic heterocycloalkyl” refer to aryl, heteroaryl, cycloalkyl,and nonaromatic heterocycle groups, respectively, that are connectedthrough an alkyl chain, e.g., benzyl, —CH₂H₂-pyridine,(3-cyclohexyl)propyl, and the like.

An “acyclic” group is a substituent that does not contain a ring. A“monocyclic” group contains only a single ring, for example, a phenylring that is not fused to another ring. A “polycyclic” group is a groupthat contains multiple fused rings, for example, naphthyl.

The term “derivative”, e.g., in the term “cycloalkyltetrahydroquinolinederivatives”, refers to compounds that have a common core structure, andare substituted with various groups as described herein. For example,all of the compounds represented in Table 1 arecycloalkyltetrahydroquinoline derivatives, and have structural formula Ias a common core.

A line across a bond in a ring, for example, the line from HO₂C— instructural formulas I-b and I-c, indicates that the represented bond canbe connected to any substitutable atom in the ring.

A “substitutable atom” is any atom such as nitrogen or carbon that canbe substituted by replacing a hydrogen atom bound to the atom with asubstituent. A “substitutable ring atom” in a ring, e.g., thesubstitutable ring carbons in Rings A to C, is any ring atom, e.g., acarbon or nitrogen, which can be substituted. For example, when X2 is acarbon, it can be bound to —H or substituted, e.g., with R2.

Suitable substituents are those that do not substantially interfere withthe pharmaceutical activity of the disclosed compound. A compound orgroup can have one or more substituents, which can be identical ordifferent. Examples of suitable substituents for a substitutable carbonatom in an alkyl, cycloalkyl, cycloalkenyl, non-aromatic heterocycle,aryl, or heteroaryl group include —OH, halogen (—Br, —Cl, —I and —F),—R, —OR, —CH₂R, —CH₂CH₂R, —OCH₂R, —CH₂OR, —CH₂CH₂OR, —CH₂OC(O)R, —O—COR,—COR, —SR, —SCH₂R, —CH₂SR, —SOR, —SO₂R, —CN, —NO₂, —COOH, —SO₃H,—NH_(2,) —NHR, —N(R)₂, —COOR, —CH₂COOR, —CH₂CH₂COOR, —CHO, —CONH₂,—CONHR, —CON(R)₂, —NHCOR, —NRCOR, —NHCONH₂, —NHCONRH, —NHCON(R)₂,—NRCONH₂, —NRCONRH, —NRCON(R)₂, —C(═NH)—NH₂, —C(═NH)—NHR, —C(═NH)—N(R)₂,—C(═NR)—NH₂, —C(═NR)—NHR, —C(═NR)—N(R)₂, —NH—C(═NH)—NH₂, —NH—C(═NR)—NHR,—NH—C(═NH)—N(R)₂, —NH—C(═NR)—NH₂, —NH—C(═NR)—NHR, —NH—C(═NR)—N(R)₂,—NRH—C(═NH)—NH₂, —NR—C(═NH)—NHR, —NR—C(═NH)—N(R)₂, —NR—C(═NR)—NH₂,—NR—C(═NR)—NHR, —NR—C(═NR)—N(R)₂, —SO₂NH₂, —SO₂NHR, —SO₂NR₂, —SH,—SO_(k)R (k is 0, 1 or 2) and —NH—C(═NH)—NH₂. Each R is independently analkyl, cycloalkyl, benzyl, aromatic, heteroaromatic, or phenylaminegroup that is optionally substituted. Preferably, R is unsubstituted. Inaddition, —N(R)₂, taken together, can also form a substituted orunsubstituted heterocyclic group, (e.g., as for NR^(c) ₂, and NR^(j) ₂)such as pyrrolidinyl, piperidinyl, morpholinyl and thiomorpholinyl.Examples of substituents on group represented by R include amino,alkylamino, dialkylamino, aminocarbonyl, halogen, alkyl,alkylaminocarbonyl, dialkylaminocarbonyloxy, alkoxy, nitro, cyano,carboxy, alkoxycarbonyl, alkylcarbonyl, hydroxy, haloalkoxy, orhaloalkyl.

Suitable substituents on the nitrogen of a heterocyclic group orheteroaromatic group include —R′, —N(R′)₂, —C(O)R′, —CO₂ R, —C(O)C(O)R′,—C(O)CH₂ C(O)R′, —SO₂R′, —SO₂ N(R′)₂, —C(═S)N(R′)₂, —C(═NH)—N(R′)₂, and—NR′ SO₂R′. R′ is hydrogen, an alkyl, alkoxy, cycloalkyl, cycloalkoxy,phenyl, phenoxy, benzyl, benzyloxy, heteroaromatic, or heterocyclicgroup that is optionally substituted. Examples of substituents on thegroups represented by R′ include amino, alkylamino, dialkylamino,aminocarbonyl, halogen, alkyl, alkylaminocarbonyl,dialkylaminocarbonyloxy, alkoxy, nitro, cyano, carboxy, alkoxycarbonyl,alkylcarbonyl, hydroxy, haloalkoxy, or haloalkyl. Preferably, R′ isunsubstituted.

EXEMPLIFICATION Example 1 Synthesis of MurA Inhibitors of StructuralFormula I-a

The disclosed compounds can be prepared by standard methods startingfrom appropriate commercially available starting materials.

Concentrated HCl (1.7 mL, 20 mmol) was added to a solution of2-aminobenzoic acid (2.74 g, 20 mmol) in 30 mL of methanol at 0°-5° C.After stirring for 15 min, glyoxylic acid methyl ester (2.8 M, 7.9 mL,22 mmol) was. The mixture was stirred for 2 h at 0°-5° C.,cyclopentadiene (1.6 mL, 20 mmol) was added. After stirring anadditional 2 h at 0°-5° C., the solid product was collected byfiltration and purified by silica gel column chromatography (petroleumether-ethyl acetate, 2:1). The pure product was obtained as a whitesolid (2.6 g, 48% yield). See Ganem, B. 1989. Organizational Chemistry2:127-128, the entire teachings of which are incorporated herein byreference.

Using the methods in the above example, compounds represented bystructural formula I, i.e., Compounds II to LXXXIV and I-m (Table 1)were prepared by starting from appropriate reagents. In Table 1,structures depicting unfilled valences on N or O, i.e., are understoodto be bonded to —H.

Compounds that are racemic, stereochemically enriched, orstereochemically pure can be prepared by an appropriate combination ofmethods selected from employing appropriate starting materials orreagents, crystallization, and chromatographic purification. See, forexample, Ahuja, S. “Chiral Separations by Chromatography”, AmericanChemical Society, 2000; Ahuja, S. “Chiral Separations: Applications andTechnology”, American Chemical Society, 1996, and references therein,the entire teachings of which are incorporated herein by reference.

Example 2 High Throughput Screen Identifies Likely MurA Inhibitors

A high throughput screen was employed on the compounds to identify thelikely MurA inhibitors depicted in Table 1. The test conditions employedMurA and MurB (UDP-N-acetylmuramate:NADP+oxidoreductase, EC 1.1.1.158)coupled enzymatic reactions carried in 96-well reaction plates.

Using appropriate stock solutions, each well was prepared to contain atotal volume of about 100 μL, containing 50 mM Tris-HCl(Tris(hydroxymethyl)aminomethane-HCl, pH 8.0), 20 mM KCl, 0.02% Brij®30(Polyethylene glycol dodecyl ether), 0.5 mM DTT (dithiothreitol), 0.1 mMUDPAG (Uridine 5′-diphospho-N-acetylglucosamine), 0.1 mMphosphoenolpyruvate (PEP), 0.1 mM NADPH (nicotinamide adeninedinucleotide phosphate), 120 ng MurA, and 40 ng MurB. The precedingchemical reagents were obtained from Sigma, St. Louis Mo.; the enzymeswere produced in house.

The wells were prepared without substrate (PEP and UDPAG) incubated fora half hour, combined with the substrate and each test compound, and theevidence of reaction was read after 1 hour of reaction time using afluorescence spectrometer at 355/460 nM for 0. 1 second. Compounds thatwere associated with an increase in fluorescence over control solutionswere identified as likely MurA inhibitors. TABLE 1 MurA Inhibitors ofStructural Formula I

II V IX

III VI X

IV VII XI

I-m VIII XII

XIII XVII XXI

XIV XVIII XXII

XV XIX XXIII

XVI XX XXIV

XXV XXX XXXVII

XXVI XXXI XXXVIII

XXVII XXXV XLVII

XXVIII XXXVI XLIX

LII LX LXXVI

LVII LXI

LVIII LXII

LIX LXXV

Example 3 Kinetic Assay of Disclosed Inhibitors Shows Potent MurAInhibition

A series of IC50 (inhibition Concentration at 50 percent) assays wereperformed in 96-well assay plates. About 60 μL of a buffer A1 was addedinto each well from column 1 to column 12. An additional 20 μL of bufferA1 was added into column 12. Buffer A1 was prepared to contain 50 mMHEPES pH 7.5(4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid), 20 mMKCl, 0.02% wt Brij 30, 0.001 mM UDPAG, 0.001 mM PEP, and 0.5 mM DTT.

Approximately 2 μL of compound solution was transferred by serialdilution from column 2 to column 11, resulting in a range of finalcompound concentrations from about 25 to about 0.049 μg/mL.

Approximately 20 μL of enzyme solution A2 was added into each well ofcolumn 1 through 11. Buffer A2 was prepared to contain 50 mM HEPES pH7.5, 20 mM KCl, 0.02% wt Brij 30, 0.001 mM UDPAG, 0.001 mM PEP, 0.5 mMDTT, and 6 μg/mL MurA.

The plated solutions were incubated for half hour, after whichapproximately 20 μL of substrate solution B was added to each well,column 1 through 11, to initiate the reaction. Buffer B is prepared as 2mM UDPAG, 0.4 mM PEP, 50 mM HEPES pH 7.5, 20 mM KCl, 0.02% wt Brij 30and 0.5 mM DTT.

After reacting for 8 minutes, 150 μL of Malachite Green was added, theresulting combination incubated for 15 minutes at ambient temperature,and the reaction result was determined by measuring absorbance at 650 nmwith a spectrometer.

The data were fit to a curve using Xlfit (ID Business Solutions,Cambridge, Mass.)). The IC₅₀ value was derived from the curve as thecompound concentration that gave 50% inhibition of the enzymaticreaction. The results are depicted in Table 2. TABLE 2 IC50 InhibitionAssay Reveals Potent MurA Inhibitors # MURa IC50 II <5 III <5 IV <5 I-m<5 V <5 VI <5 VII <5 VIII <5 IX <5 X <5 XI <5 XII <5 XIII <5 XIV <5 XV<5 XVI <5 XVII <5 XVIII <5 XIX <5 XX <5 XXI <5 XXII ≧5, <33 XXIII ≧5,<33 XXIV ≧5, <33 XXV ≧5, <33 XXVI ≧5, <33 XXVII ≧5, <33 XXVIII ≧5, <33XXX ≧33 XXXI ≧33 XXXV ≧33 XXXVI ≧33 XXXVII ≧33 XXXVIII ≧33 XLVII ≧33XLIX ≧33 LII ≧33 LVII ≧33 LVIII ≧33 LIX ≧33 LX ≧33 LXI ≧33 LXII ≧33 LXXV≧33 LXXVI ≧33

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. A method of treating a subject for a bacterial infection, comprisingadministering to a subject in need of treatment for a bacterialinfection an effective amount of a compound represented by structuralformula I:

or a pharmaceutically acceptable salt, solvate, or hydrate thereof,wherein: Ring A is a 5 or 6 membered cycloalkyl or cycloalkenyl group,optionally substituted with halogen or optionally′halogenated C1-C3alkyl or alkoxy; X2 and X3 are each carbon, or one is nitrogen and theother is carbon; and Rings B and C are optionally and independentlysubstituted at any substitutable ring carbon, provided that one or twosubstitutable ring carbons in Rings B and C are substituted with anacidic group. 2 .The method of claim 1, wherein the subject is a human.3. The method of claim 2, wherein the infection is caused by a bacteriumthat expresses phosphoenolpyruvate: UDP-N-acetyl-D-glucosamine1-carboxyvinyltransferase.
 4. The method of claim 2, wherein theinfection is caused by a bacterium of a genus selected Allochromatium,Acinetobacter, Bacillus, Campylobacter, Chlamydia, ChlamydophilaClostridium, Citrobacter, Escherichia, Enterobacter, Enterococcus,Francisella, Haemophilus, Helicobacter, Klebsiella, Listeria, Moraxella,Mycobacterim, Neisseria, Proteus, Pseudomonas, Salmonella, Serratia,Shigella, Stenotrophomonas, Staphyloccocus, Streptococcus,Synechococcus, Vibrio, and Yersina.
 5. The method of claim 4 wherein thebacterial infection is from [correct list?] Allochromatium vinosum,Acinetobacter baumanii, Bacillus anthracis, Campylobacter jejuniChlamydia trachomatis, Chlamydia pneumoniae, Clostridium spp.,Citrobacter spp., Escherichia coli, Enterobacter spp., Enterococcusfaecalis., Enterococcus faecium, Francisella tularensis, Haemophilusinfluenzae, Helicobacter pylori, Klebsiella spp., Listeriamonocytogenes, Moraxella catarrhalis, Mycobacterium tuberculosis,Neisseria meningitidis, Neisseria gonorrhoeae, Proteus mirabilis,Proteus vulgaris, Pseudomonas aeruginosa, Salmonella spp., Serratiaspp., Shigella spp., Stenotrophomonas maltophilia, Staphyloccocusaureus, Staphyloccocus epidermidis, Streptococcus pneumoniae,Streptococcus pyogenes, Streptococcus agalactiae, Yersina pestis, andYersina enterocolitica.
 6. The method of claim 5 wherein the acidicgroup is selected from —(CO)OH, —(CS)OH, —(SO)OH, —SO₃H, —OSO₃H,—P(OR^(a))(OH), —(PO)(OR^(a))(OH), —O(PO)(OR^(a))(OH), or—B(OR^(a))(OH), wherein R^(a) is —H or optionally substituted aryl,aralkyl, heteroaryl, heteroaralkyl, or C1 to C4 alkyl.
 7. The method ofclaim 6, wherein the compound is represented by structural formula I-a:


8. The method of claim 7, wherein the compound is represented bystructural formula I-a′:

wherein: R1, R2, R3, and R4 are independently —H, halogen, —NO₂, —CN,—(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) _(2,)—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4alkyl, C1 to C4 alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6 alkoxyalkyl;wherein: each R^(b) and R^(d) is independently —H or optionallysubstituted aryl, aralkyl, heteroaryl, heteroaralkyl, or C1 to C4 alkyl;and each R^(c) is independently —H or optionally substituted C1 to C4alkyl, aryl, or aralkyl, or NR^(c) ₂ is an optionally substitutednonaromatic heterocycle.
 9. The method of claim 8 wherein at least twoof R1 to R4 are —H.
 10. The method of claim 9 wherein: one or two of R1to R4 are each independently —F, —Cl, —Br, —(CO)R^(b), —(CO)OR^(b),—(CO)NR^(c) ₂, —NR^(c) ₂, —NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b),—NR^(d)(CO)NR^(c) ₂, —NR^(d)(CO)PhNR^(d)(CO)R^(b), or optionallysubstituted phenyl, benzyl, pyridyl, methylpyridyl, or optionallyhalogenated C1 to C4 alkyl or C1 to C4 alkoxy; wherein each R^(b),R^(c), and R^(d) is independently —H, or optionally substituted C1 to C4alkyl or phenyl, or each NR^(c) ₂ is an optionally substitutedmorpholinyl, piperidyl, or piperazyl.
 11. The method of claim 10 whereinthe compound is represented by one of the following structural formulas:


12. The method of claim 8 wherein at least one of R1 to R4 is —CO₂H, ora C1 to C4 alkyl ester thereof.
 13. The method of claim 12 wherein thecompound is represented by one of the following structural formulas:


14. The method of claim 6, wherein the compound is represented bystructural formula I-b:

wherein Y is optionally substituted C1 to C4 alkyl, C1 to C4 alkoxy,phenyl, pyridyl, or —NR^(j) _(2,) wherein each R^(j) is independently—H, C1 to C4 alkyl, aryl, or aralkyl, or NR^(j) ₂ is a nonaromaticheterocycle.
 15. The method of claim 14, wherein the compound isrepresented by structural formula I-b′:

wherein: R1, R2, R3, and R4 are independently —H, halogen, —NO₂, —CN,—(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4alkyl, C1 to C4 alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6 alkoxyalkyl,wherein at least one of R1 to R4 is —CO₂H; wherein: each R^(b) and R^(d)is independently —H or optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, or C1 to C4 alkyl; and each R^(c) is independently —H oroptionally substituted C1 to C4 alkyl, aryl, or aralkyl, or NR^(c) ₂ isan optionally substituted nonaromatic heterocycle.
 16. The method ofclaim 15 wherein at least two of R1 to R4 are —H.
 17. The method ofclaim 16, wherein the compound is represented by one of the followingstructural formulas:


18. The method of claim 6, wherein the compound is represented bystructural formula I-c:


19. The method of claim 18, wherein the compound is represented bystructural formula I-c′:

wherein: R1, R2, and R4 are independently —H, halogen, —NO₂, —CN,—(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4alklyl, C1 to C4 alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6alkoxyalkyl; wherein: each R^(b) and R^(d) is independently —H oroptionally substituted aryl, aralkyl, heteroaryl, heteroaralkyl, or C1to C4 alkyl; and each R^(c) is independently —H or optionallysubstituted C1 to C4 alkyl, aryl, or aralkyl, or NR^(c) ₂ is anoptionally substituted nonaromatic heterocycle.
 20. The method of claim19, wherein R1, R2, and R4 are independently —H, —F, —Cl, —Br, —NO₂,—CN, —(CO)R^(b), —(CO)NR^(c) ₂, —NR^(c) ₂, —NR^(d)(CO)R^(b),—NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂, —NR^(d)SO₂R^(b),or optionally halogenated C1 to C4 hydroxy alkyl, C1 to C4 alkyl, or C1to C4 alkoxy; wherein each R^(b), R^(c) and R^(d) is independently —H orC1 to C4 alkyl; or NR^(c) ₂ is a nonaromatic heterocycle.
 21. The methodof claim 20 wherein at least two of R1, R2, and R4 are —H.
 22. Themethod of claim 21 wherein the compound is represented by structuralformula I-m:


23. A compound represented by structural formula I-a′:

or a pharmaceutically acceptable salt, solvate, or hydrate thereof,wherein: R1, R2, R3, and R4 are independently —H, —(CO)R^(b),—(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b), —(SO)OR^(b),—SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂, —O(PO)(OR^(b))₂,—B(OR^(b))₂, —NR^(c) ₂, —NR^(d)(CO)R^(b), NR^(d)(CO)OR^(b),—NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂, —NR^(d)SO₂R^(b), or an optionallysubstituted aryl, aralkyl, heteroaryl, heteroaralkyl, C3 to C7cycloalkyl, or nonaromatic heterocycle; wherein: each R^(b) and R^(d) isindependently —H or optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, or C1 to C4 alkyl; and each R^(c) is independently —H oroptionally substituted C1 to C4 alkyl, aryl, or aralkyl, or NR^(c) ₂ isan optionally substituted nonaromatic heterocycle.
 24. The compound ofclaim 23 wherein at least two of R1 to R4 are —H.
 25. The compound ofclaim 24 wherein: one or two of R1 to R4 are each independently—(CO)R^(b), —(CO)OR^(b), —(CO)NR^(c) ₂, —NR^(c) ₂, —NR^(d)(CO)R^(b),—NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —NR^(d)(CO)PhNR^(d)(CO)R^(b), oroptionally substituted phenyl, benzyl, pyridyl, or methylpyridyl;wherein each R^(b), R^(c), and R^(d) is independently —H, or optionallysubstituted C1 to C4 alkyl or phenyl, or each NR^(c) ₂ is an optionallysubstituted morpholinyl, piperidyl, or piperazyl.
 26. The compound ofclaim 25 wherein the compound is represented by one of the followingstructural formulas:


27. A compound represented by structural formula I-a″:

or a pharmaceutically acceptable salt, solvate, or hydrate thereof,wherein Ring B is optionally substituted at any substitutable ringcarbon, and Z is —H or a C1 to C4 alkyl group.
 28. The compound of claim27, wherein the compound is represented by structural formula I-a′:

wherein: R1, R2, R3, and R4 are independently —H, halogen, —NO₂, —CN,—(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂ ,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4alkyl, C1 to C4 alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6 alkoxyalkyl,wherein at least one of R1 to R4 is —(CO)OR^(b); wherein: each R^(b) andR^(d) is independently —H or optionally substituted aryl, aralkyl,heteroaryl, heteroaralkyl, or C1 to C4 alkyl; and each R^(c) isindependently —H or optionally substituted C1 to C4 alkyl, aryl, oraralkyl, or NR^(c) ₂ is an optionally substituted nonaromaticheterocycle.
 29. The compound of claim 28, wherein the compound isrepresented by one of the following structural formulas:


30. A compound represented by structural formula I-b:

or a pharmaceutically acceptable salt, solvate, or hydrate thereof,wherein: Ring B is optionally substituted at any substitutable ringcarbon, provided that one or two substitutable ring carbons in Ring Bare substituted with an acidic group; and Y is optionally substituted C1to C4 alkyl, C1 to C4 alkoxy, phenyl, pyridyl, or —NR^(j) ₂; whereineach R^(j) is independently —H, C1 to C4 alkyl, aryl, or aralkyl, orNR^(j) ₂ is a nonaromatic heterocycle.
 31. The compound of claim 30wherein the acidic group is selected from —(CO)OH, —(CS)OH, —(SO)OH,—SO₃H, —OSO₃H, —P(OR^(a))(OH), —(PO)(OR^(a))(OH), —O(PO)(OR^(a))(OH), or—B(OR^(a))(OH), wherein R^(a) is —H or optionally substituted aryl,aralkyl, heteroaryl, heteroaralkyl, or C1 to C4 alkyl.
 32. The compoundof claim 31, wherein the compound is represented by structural formulaI-b′:

wherein: R1, R2, R3, and R4 are independently —H, halogen, —NO₂, —CN,—(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) ₂, NR^(d)(CO)R^(b),—NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂, —NR^(d)SO₂R^(b),or an optionally substituted aryl, aralkyl, heteroaryl, heteroaralkyl,C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4 alkyl, C1 to C4alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6 alkoxyalkyl; provided thatat least one of R1 to R4 is —CO₂H; wherein each R^(b) and R^(d) isindependently —H or optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, or C1 to C4 alkyl; and each R^(c) is independently —H oroptionally substituted C1 to C4 alkyl, aryl, or aralkyl, or NR^(c) ₂ isan optionally substituted nonaromatic heterocycle.
 33. The compound ofclaim 32 wherein at least two of R1 to R4 are —H.
 34. The compound ofclaim 33 wherein one of R1 to R4 is —CO₂H.
 35. The compound of claim 34,wherein the compound is represented by one of the following structuralformulas:


36. A compound represented by structural formula I-c:

or a pharmaceutically acceptable salt, solvate, or hydrate thereof,wherein Ring B is optionally substituted at any substitutable ringcarbon.
 37. The compound of claim 36, wherein the compound isrepresented by structural formula I-c′:

wherein: R1, R2, and R4 are independently —H, halogen, —NO₂, —CN,—(CO)R^(b), —(CO)OR^(b), —(CO)O(CO)R^(b), —(CS)OR^(b), —(CS)R^(b),—(SO)OR^(b), —SO₃R^(b), —OSO₃R^(b), —P(OR^(b))₂, —(PO)(OR^(b))₂,—O(PO)(OR^(b))₂, —B(OR^(b))₂, —(CO)NR^(c) ₂, —NR^(c) ₂,—NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b), —NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂,—NR^(d)SO₂R^(b), or an optionally substituted aryl, aralkyl, heteroaryl,heteroaralkyl, C3 to C7 cycloalkyl, nonaromatic heterocycle, C1 to C4alkyl, C1 to C4 alkoxy, C1 to C4 hydroxy alkyl, or C2 to C6 alkoxyalkyl;wherein: each R^(b) and R^(d) is independently —H or optionallysubstituted aryl, aralkyl, heteroaryl, heteroaralkyl, or C1 to C4 alkyl;and each R^(c) is independently —H or optionally substituted C1 to C4alkyl, aryl, or aralkyl, or NR^(c) ₂ is an optionally substitutednonaromatic heterocycle.
 38. The compound of claim 37, wherein R1, R2,and R4 are independently —H, —F, —Cl, —Br, —NO₂, —CN, —(CO)R^(b),—(CO)NR^(c) ₂, —NR^(c) ₂, —NR^(d)(CO)R^(b), —NR^(d)(CO)OR^(b),—NR^(d)(CO)NR^(c) ₂, —SO₂NR^(c) ₂, —NR^(d)SO₂R^(b), or optionallyhalogenated C1 to C4 hydroxy alkyl, C1 to C4 alkyl, or C1 to C4 alkoxy;wherein each R^(b), R^(c) and R^(d) is independently —H or C1 to C4alkyl; or NR^(c) ₂ is a nonaromatic heterocycle.
 39. The compound ofclaim 38 wherein two of R1, R2, and R4 are —H.
 40. The compound of claim39 wherein the compound is represented by structural formula I-m:


41. A method of identifying a MurA inhibitor, comprising: contactingMurA with phosphoenolpyruvate and a test compound; determining areaction rate between the phosphoenolpyruvate and MurA; and identifyingthe test compound as a MurA inhibitor when the rate of reaction in thepresence of the test compound is less than a reaction rate in theabsence of the test compound.
 42. The method of claim 41, furthercomprising conducting the reaction in the presence of MurB and uridine5′-diphospho-N-acetylglucosamine.